First election sejm of the Commonwealth. Sejm in the Kamień village, in the vicinity of Warsaw. 1573.

The sejm was convened at the convocation sejm on 28 January 1573, during which the order of the elections was adopted, as well as the interrex for the interregnum. At the convocation the pre-election sejmiks were also called and took place in March 1573. During the proceedings, which began on 5 April 1573, numerous foreign missions were heard, including these sent by the candidates to the first election for the king of the Commonwealth, which sent its own missions. The demands of the soldiers, to pay their overdue wages, were examined. A commission was also established, to investigate abuses of royal court (in the period preceding king’s Sigismund II Augustus death). Conscription universal was adopted. There was also a discussion about revising the laws of the Commonwealth and, as a result of the debate, on 12 May 1573 a resolution was adopted, determining principles of the political system. They were later called the Henrician Articles, as a reference to the first king who was supposed to approve them. During the proceedings of the election sejm, on 11 May 1573, the deputies chose Henry de Valois to be the next the king and he was announced the king on 16 May same year. During the election sejm of 1573 an agreement, called pacta conventa, between the “estates of the Commonwealth” and the newly elected king, stipulating commitments of the elect, signed by him before coming to the throne. They were presented to the king-elect Henry by the mission of the “Polish estates”, which set out to Paris, to announce the result of the election. The sejm finished proceedings on 20 May 1573.